Watch movement for wristwatches



Aug. '12, 1969 H. KOCHER WATCH MOVEMENT FOR WRISTWATCHBS 5 Sheets-Sheet 1 Filed Aug. 1, 196'? #44 (mag MENTOR. 533 c Km flrroeutrs Aug. 12, 1969 H. KOCHER 3, 6 1

WATCH MOVEMENT FOR WRISTWATCHES Filed Aug. 1, 1967 s Sheets-Sheet 2 I N ENTOR. Was 0045a Aug. 12, 1969 H. KOCHER WATCH MOVEMENT FOR WRISTWATCHES Fil ed Aug. 1, 1967 5 Sheets-Sheet s %/5 Kacmse INVENTOR.

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H. KOCHER WATCH MOVEMENT FOR WRISTWATCHES Aug. 12, 1969' 5 Sheets-Sheet 5 Filed" Ans: 1967 m WE MlV//////////// ll a mm M r/i yrmewfs United States Patent 3,460,341 WATCH MOVEMENT FUR WRISTWATCHES Hans Kocher, Buren-sur-Aar, Switzerland, assignor to Buren Watch Company, A., Buren-sur-Aar, Switzerland, a corporation of Switzerland Filed Aug. 1, 1967, Ser. No. 657,657 Claims priority, applicgtigg 3Gvgrmany, Dec. 17, 1966,

Int. Cl. G04b 5/02 US. Cl. 58-82 9 'Claims ABSTRACT OF THE DISCLOSURE Background of the invention Field of the invention.--The invention relates to mechanical watch movements for Wristwatches, which comprise a spring motor housed in a barrel, a gear train driven by said barrel, an escapement mechanism actuated by said gear train and a regulating balance wheel driven by said escapement mechanism and controlling the same by oscillating at high frequency. Under a balance wheel oscillating at high frequency, it should be understood hereinafter a balance wheel which makes at least 30,000 half oscillations per hour in contradist'mction to the usual balance wheels oscillating at a frequency ranging between 18,000 and 22,000 half oscillations per hour.

Description of the prior art.-The known Wristwatches provided with a balance wheel oscillating at high frequency, when compared with Wristwatches with a usual balance wheel, have the advantage that the balance wheel oscillations are not significantly disturbed by the arm movements of the person carrying such a watch. As a consequence thereof, a watch provided with a balance wheel oscillating at high frequency is substantially more precise than a watch having a conventional balance wheel. As a matter of fact, it is even as precise as an electronic or electric watch comprising a regulating and driving member which is controlled electronically for instance by means of a transistorized amplifier. I

The known watches having a balance wheel oscillating at a high frequency have, however, the drawback that they dissipate a substantially greater amount of energy than the watches equipped with a balance wheel oscillating at a usual frequency. As a result of the higher frequency of the balance wheel, the escape wheel speed is obviously higher and the path through which a tooth of the escape wheel travels during a predetermind time interval is accordingly longer. Moreover, the impulses which the escape wheel has to impart to a balance wheel oscillating at a high frequency for entertaining the oscillations thereof are stronger than with a balance wheel oscillating at the usual frequency. Recalling that the definition of the mechanical work accomplished by a force acting along a predetermined path is equal to the product of the force by the length of the path through which the force has acted, it will be observed that doubling the frequency of a balance Wheel can only be accomplished by increasing the power of the escape wheel much $46,341 Patented Aug. 12, 1969 more than twice. Since the power of the escape 'wheel stands in a ratio with the energy dissipated, and since the amount of energy which can be stored up in a barrel is strongly limited by the volume of the latter, it appears that merely substituting a balance wheel oscillating at a high frequency, for instance 36,000 half oscillations per hour, will result in dissipating the maxium of energy stored in the barrel in a time substantially shorter than half the running time of the slower balance wheel. If the movement considered may run during 45 hours with a balance wheel making 18,000 half oscillations per hour until the total energy which can be stored up in the barrel is dissipated, the same movement will obviously not be able to run during a full day with a balance wheel making 36,000 half oscillations per hour. In order to obtain a running time of 24 hours, the moment of inertia of the faster balance wheel must be substantially smaller than that of the slower one.

Simply by reducing the moment of inertia of the balance wheel which is intended for oscillating at a high frequency, it is, however, not yet possible to keep the dissipation of energy low enough in order that the watch could satisfactorily be wound up by a conventional selfwinding mechanism actuated by a rotary weight. Practice has indeed shown that a self-winding watch must be provided with a spring motor which is able to store up energy for a running period of at least 40 hours. This period has proved to be the shortest one which can provide for compensation for the quite different conditions in which the watches are carried in use, and which result from the important discrepancies due to all the possible temperaments of the persons who buy such a watch. 011 the one hand, the self-winding mechanism must be sensitive enough in order that the smooth arm movements of the calmest watch owner store up by day such an amount of energy that the watch runs overnight. On the other hand, a sportsman should not wind up the watch to such an extent that it runs during longer periods of time in an overwound state.

Among the known watches which comprise a balance wheel oscillating at high frequency, there is thus none which could be provided with a self-winding mechanism operating under the required conditions.

Moreover, in addition to the energy requirement, there is still a further condition which self-winding watches must be able to fulfill. In most of the cases, a self-winding watch is required to utilize a directly driven sweep second. In order that the sweep second be driven directly, it must be set on the shaft of a wheel of the gear train driven by the barrel and actuating the escapement mechanism. Since the wheel of that gear train, which runs at the convenient speed for the sweep second, is the fourth wheel, this fourth wheel must accordingly be journalled in the center of the watch movement.

The problem to be solved thus not merely consists in improving a watch movement having a balance wheel oscillating at a high frequency in such manner that a selfwinding mechanism can be associated therewith, but the improved watch movement must additionally be conceived so that it may be equipped with a sweep second.

Summary of the invention The watch movement according to the invention cornprises a barrel which extends beyond the center of the watch movement.

A barrel enlarged in that way need not be made substantially thicker than that of a conventional movement having a balance wheel oscillating at the usual frequency in order to be able to store up the additional amount of energy required by a balance wheel oscillating at a high frequency, because the capacity of the barrel increases with the diameter not only linearly, as with the thickness, but quadratically.

As regards the location of the fourth wheel in the center of the watch movement, any interference with the barrel of the watch according to the invention, which extends beyond the center, must of course be avoided. Therefore, the upper bearings of the fourth wheel and the escape wheel of the watch movement can, according to a further object of the invention, be carried by a bridge located on a level comprised between the barrel and the base plate and having at least a portion overlapped by the barrel, while the upper bearings of the second wheel and of the third wheel can be carried by another bridge which is located on the same level as the barrel, without overlapping the same.

Above the lower bridge, which carries the upper bearings of the fourth wheel and of the escape wheel, there is accordingly a space within the overall boundaries of the movement, which remains free and can, according to still a further object of the invention, advantageously be used for accommodating a unit comprising a pair of bridges secured to each other and carrying gear means of the self-winding mechanism, thus avoiding an additional increase of the total movement height due to the accommodation of that part of the self-winding mechanism.

Brief description of the drawings One embodiment of the watch movement according to the invention is represented diagrammatically and by way of example in the annexed drawings, in which:

FIGURE 1 is a plane view of the movement at a mounting stage in which only some parts have been assembled;

FIGURE 2 is a sectional view along line IIII of FIGURE 1 on a larger scale;

FIGURE 3 is a partial plane view on the dial side of the watch movement;

FIGURE 4 is a sectional view along line IVIV of FIGURE 3 on a larger scale;

FIGURE 5 is a plane view of the watch movement, the winding weight of the self-winding mechanism having been cut away; and

FIGURES 6-8 are part sectional views on a larger scale and taken along lines VIVI, VIIVII, and VIIIVII1, respectively, of FIGURE 5.

Description of the preferred embodiment Like well known watch movements, that represented in the drawings comprises an oifcentered center wheel 1, a third wheel 2, a fourth wheel 3 journalled in the center of the watch movement, an escape wheel 4, an escapement lever 11 having a lower pivot journalled in a bearing carried by the base plate 5 and an upper pivot journalled in a bearing carried by an escape bridge 6, and a balance wheel 7 arranged for oscillating at a high frequency and comprising a lower pivot journalled in a bearing carried by the base plate 5 and an upper pivot journalled in a bearing carried by a balance cock 8. With the only exception of the second wheel 1, all the wheels of the drive train described have their lower pivots journalled in bearings carried by the base plate 5. The upper pivots of the wheels of that train are journalled in bearings carried by two separate bridges 9, 10, which are not located on the same level with respect to the base plate 5. Bridge 10, carrying the upper bearings for the pivots of wheels 3 and 4, is lower than bridge 9, which carries the upper bearings for the pivots of wheels 1 and 2. Bridge 10 is entirely embedded in a recess 12 of base plate 5 so that its upper surface is substantially lower than a bearing surface 13 of the base plate which extends along the periphery thereof (FIGURE 8), while the upper surface of bridge 9 lies above the bearing surface 13.

The gear train described is driven by a barrel 14, the diameter of which is larger than the radius of the watch movement. Barrel 14 is located within the watch movement so that it has no portion protruding from the overall boundaries of the movement framework. Under these conditions, barrel 14 clearly extends beyond the watch movement center. The diameter of the barrel, as well as the thickness thereof, are calculated in such manner that this barrel will be able to receive a main spring 15 (FIGURE 6) which is firstly strong enough in order to drive the movement described, and which is secondly long enough in order to be able to store up a sufiicient amount of energy for driving the watch movement at least during 40 hours, i.e., during a period having the length required with self-winding watches. With respect to the barrels of the self-winding watches comprising a balance wheel oscil: lating at a usual frequency, the barrel 14 is only a little thicker. The volume required by the stronger and longer main spring is thus chiefly obtained by the fact that the diameter of the barrel has been substantially increased with respect to the watches provided with a balance wheel oscillating at a usual frequency. As shown in FIGURES 2, 6 and 8, barrel 14 overlaps bridge 10, but it extends at the side of bridge 9. Barrel 14 has a lower pivot journalled in a bearing carried by base plate 5 and an upper pivot journalled in a bearing carried by the barrel bridge 16, which is located on a level still higher than that of bridge 9 with respect to base plate 5 (FIGURE 8).

The shaft of the fourth wheel 3 serves as a support for a sweep second (not shown) which is thus driven directly because wheel 3 forms part of the gear train driven by barrel 14 and actuating the escapement mechanism of the watch movement. A minute hand and an hour hand (not shown) are set in the usual manner on a cannonpinion 17 and on a hour wheel 18, respectively. In contradistinction to the fourth wheel, cannon-pinion 17 and wheel 1-8 are driven indirectly, as well known to those skilled in the art. For that purpose, the center wheel shaft extends through an opening 19 of base plate 5 and the lower pivot of the center wheel is journalled in a bearing carried by a plate 20, which is secured onto the base plate 5 on the dial side thereof. A pinion 21 frictionally engages a lower portion of the center wheel shaft (FIG- URES 2, 3, and 4). Pinion 21 stands in meshing relation with a minute wheel 22 which drives the cannonpinion 17 and carries a pinion 23 driving the hour wheel 18. The minute wheel 22 further carries a projection 24 extending within an elongated slot 25 provided in base plate 5. A spring 26 acts on projection 24 in such a direction that wheel 22 will be pressed against pinion 21 and cannon-pinion 17 and provide in that way for a connection between the gear train driven by the barrel ad the motion work of the watch, which does not allow any free play of the minute hand.

The watch hands can be set in the usual manner by means of a winding and hand-setting stem 27 driving a shiftable clutch wheel 28 and two intermediate wheels 29, 30.

The watch movement according to the invention further comprises a self-winding mechanism operated by a winding weight 31 journalled to the center of the watch movement and arranged for driving the ratchet wheel 32 set on the barrel arbor. This self-winding mechanism comprises gear means which connect the winding weight to the ratchet wheel and which include a reversed input unidirectional output mechanism. The winding weight 31 carries a winding wheel 33 which meshes with the first wheel 34 (FIGURE 6) of a gearing unit of the self-winding mechanism. Wheel 34 in turn simultaneously meshes with the two upper wheels of the wheel pairs 35 and 36, each of which forms a free-wheel mechanism. The gearing unit represented operates in such manner that the pinion 37, which is coaxial to the pair of wheels 36, always rotates in the same direction independently of the direction into which the winding weght 31 moves. Pinion 37 drives ratchet wheel 32 by means of three intermediate wheels 38, 39, 40 and a pinion 41. The different gears of the self-winding gear train are journalled in bearings car ried by two bridges 43, 44, which are secured to each other by means of a screw 42 so that they can be handled like a single piece when assembling the watch movement itself. The gearing unit of the self-winding mechanism is secured on the bearing surface 13 to the base plate 5 so as to be located over bridge and at the side of bridge 9. As shown in FIGURE 8, the upper bridge 43 of this unit is substantially flush with the barrel bridge 16. The pair of wheels 35 has, however, a portion extending over bridge 9.

In order that weight 31 may wind up the main spring 15, the former not only comprises a heavy peripheral stepped portion 31a like the conventional winding weights of the usual winding watches, which moves around the likewise stepped bridges of the watch movement frame, but the weight 31 additionally comprises a heavy web portion 31b extending between the periphery heavy portion 31a and a hub portion. Web portion 31b is accordingly made out of a heavy material and it is thicker than with the usual self-winding watches comprising a balance wheel oscillating at a usual frequency.

The watch movement represented in the drawing still comprises a manual winding mechanism (FIGURES 5 and 7) by means of which the main spring 15 can be wound up at will through the winding stem 27, the shiftable clutch wheel 28, the winding pinion 45, the crown wheel 46, the intermediate long pinion 47 and a travelling wheel 50 which is set on a crescent-like projection 48 of barrel bridge 16 so as to be shiftable in a substantially tangential direction with respect to the ratchet wheel 32. Wheel 50 stands under the action of a return spring 49 urging wheel 50 in the direction of pinion 47. Independently of its position about projection 48, wheel 50 always remains in meshing relation with ratchet wheel 32.

In spite of the unusual sizes of the barrel, it can be observed that the available space within the overall boundaries of the movement framework has been judiciously filled up without any substantial loss by the different movable parts of the movement and while keeping the fourth wheel in the center thereof. With respect to the usual barrels, the large barrel used in the watch movement according to the invention has moreover the advantage that it affords both for an easier manufacture of the same and for an easier adjustment of the sliding brakespring which has to be provided for self-winding watches for preventing the main spring from breaking upon overwinding the same.

The free space appearing in the drawing under barrel 14 serves for the accommodation of a calendar mechanism (not shown).

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive.

What is clamied and desired to be secured by United States Letters Patent is:

1. In a mechanical watch movement for Wristwatches, comprising: a spring motor housed in a barrel, a gear train driven by said barrel, an escapement mechanism actuated by said gear train, a regulating balance wheel driven by and controlling said escapement mechanism and carrying out at least 30,000 half oscillations per hour, and a self-winding mechanism, said barrel extending beyond the center of the movement.

2. The watch movement according to claim 1 wherein said barrel has a diameter larger than the radius of the movement and extends from adjacent the periphery thereof.

3. The watch movement according to claim 1 wherein the gear train comprises four wheels.

4. The watch movement of claim 1, in which said gear train comprises an off-centered center wheel, a third wheel, a fourth wheel journalled in the center of the watch movement and an escape wheel, and in which a framework carries pivot bearings for journalling the wheels of said gear train, said framework comprising a base plate extending on one side of said gear train and of the barrel, a first bridge secured to said base plate and located on a level comprised between the barrel and the base plate, said first bridge carrying one pivot bearing of said fourth wheel and one pivot bearing of said escape wheel and having at least a portion overlapped by said barrel, and a second bridge also secured to said base plate and located substantially on the same level as said barrel without overlapping the same, said second bridge carrying one pivot bearing of said center wheel and one pivot bearing of said third wheel.

5. The watch movement of claim 4, in which said framework comprises a barrel bridge secured to said base plate and carrying one pivot bearing of said barrel, and a pair of bridges secured to each other and forming a single unit carrying gear means of the self-winding mechanism, said base plate comprising a bearing surface at its periphery and being provided with a recess extending from said bearing surface towards the center of the movement, said first bridge being secured to said base plate within said recess so as to be entirely embedded in the base plate, below the level of said bearing surface, the unit comprising said pair of bridges being secured to the base plate onto said bearing surface and extending substantially on the same level as said barrel bridge.

6. In a mechanical watch movement for Wristwatches, the combination of a spring motor housed in a barrel extending from the periphery of the watch movement inwards, beyond the center thereof, an escapement mechanism comprising a regulating balance wheel adjusted for carrying out at least 30,000 half oscillations per hour, a base plate having said barrel and said balance wheel arranged thereon side by side near the periphery thereof, a gear train connecting said barrel with said escapement mechanism and arranged over the area of said base plate left free by said barrel and said balance Wheel, two wheel bridges for said gear train secured side by side to said base plate, but extending on different levels, the lower one of said wheel bridges having a portion extending under said barrel, self-winding gear means operatively connected to said spring motor for winding it up, a supporting frame for said self-winding gear means located over the lower one of said wheel bridges, and a winding weight mounted for free rotation above and around the watch movement and driving said self-winding gear means.

7. In a mechanical watch movement for Wristwatches the combination of: a spring motor housed in a barrel, a gear train driven by said barrel, an escapement mechanism actuated by said gear train, a regulating balance wheel driven by and controlling said escapement mechanism, said balance wheel being adjusted for carrying out at least 30,000 half oscillations per hour; a basic framework comprising: a base plate, a barrel bridge, twO wheel bridges and a balance cock for journalling said barrel, the gears of said gear train and said balance Wheel, said base plate having a first sector arranged for receiving said barrel bridge, a second sector adjacent to said first sector and arranged for receiving one of said two wheel bridges, a third sector adjacent to said second sector and arranged for receiving the other wheel bridge, one of said two wheel bridges extending over said base plate on a lower level than the other wheel bridge, a fourth sector adjacent both to said first and to said third sector and arranged for receiving said balance wheel, an auxiliary framework for a self-winding mechanism operatively connected to said spring motor for winding it up, said auxiliary framework extending over the lower one of said two wheel bridges, above the base plate sector arranged for receiving said lower wheel bridge, and a winding weight mounted for free rotation above and around the watch movement, coaxially thereto, for actuating said self-winding mechanism, said barrel being located on a level higher than said lower wheel bridge and extending beyond the center of the Watch movement.

8. In a mechanical watch movement for Wristwatches, the combination of a spring motor housed in a barrel, a gear train driven by said barrel and including an olfcentered center wheel, a third wheel, a fourth wheel 10- cated in the center of the watch movement and an escape wheel, an escapement mechanism actuated by said gear train, a regulating balance wheel driven by and controlling said escapement mechanism, said balance wheel being adjusted for carrying out at least 30,000 half oscillations per hour; a basic framework comprising: a base plate, a barrel bridge secured to said base plate and carrying the upper bearing of said barrel, a first wheel bridge secured to said base plate on the side of said barrel bridge and carrying the upper bearings of said off-centered center wheel and of said third wheel, a second wheel bridge secured to said base plate on the side of said first wheel bridge opposed to that adjacent to said barrel bridge, said second wheel bridge lying on a level lower than that of said first wheel bridge and carrying the upper bearings of said fourth wheel and of said escape wheel; an auxiliary framework for a self-winding mechanism operatively connected to said spring motor for winding it up, said auxiliary framework being secured to said base plate and eX- tending over said second wheel bridge, and bearing means provided in the center of the watch movement on one of said bridges, for a winding weight mounted for free rotary motion and actuating said self-winding mechanism, said barrel extending from the periphery of the watch movement inwards, beyond the center thereof, between said second wheel bridge and the bearing means provided for said winding weight.

9. The combination of claim 8 in which said auxiliary framework comprises a pair of bridges secured to each other and forming a single unit, said base plate comprising a bearing surface at its periphery and being provided with a recess extending from said bearing surface towards the center of the movement, said second wheel bridge being secured to said base plate within said recess so as to be entirely embedded in the base plate, below the level of said bearing surface, the auxiliary framework being secured to the base plate onto said bearing surface thereof and extending substantially on the same level as said barrel bridge.

References Cited UNITED STATES PATENTS 3,109,281 11/1963 Polo 58--82 FOREIGN PATENTS 100,208 3/1917 Great Britain.

ROBERT S. WARD, 111., Primary Examiner GEORGE H. MILLER, JR., Assistant Examiner U.S. Cl. X.R. 58-86 

